Ink distributing device of offset printing press



1963 KATSUJI AKIYAMA 3,100,441

INK DISTRIBUTING DEVICE 0F OFFSET PRINTING PRESS Filed Jan. 31, 1961 United States Patent 3,100,441 INK DISTRIBUTING DEVICE 0F OFFSET PRINTING PRESS Katsuji Akiyama, 996 Nishiarai, Adachi-ku,

Tokyo, Japan Filed Jan. 31, 1961, Ser. No. 86,020 2 Claims. (Cl. 101-350) This invention relates to olfset printing presses, and more particularly, to improvements in ink supplying and distributing devices to be used in such presses.

In the ink distributing device of an oifset printing press of conventional type, a number of inking rollers having small but equal diameters are used for applying ink to the printing plate and such inking rollers are arranged to receive the supply of ink in contacting metal rollers in reciprocating movement. In a construction of this kind, each of said small inking rollers is only capable of completing inking to the entire surface of the printing plate by making a number of revolutions, so that when the cylinder is rotating, enough ink will be supplied to each inking roller while the part other than the printing plate is passing. However as the inking of the printing plate starts, almost all of the ink will be taken away to the printing plate during the first revolution of a roller. As the result, it is almost impossible to avoid the tendency of the first half of the print becoming darker than the print of the last half.

Furthermore in an olfset printing press, water is used and it is a well-known fact that the water used is also often the cause of an undesirable eifect appearing in the various forms of prints produced. As one of such defects, stripe-like unevenness appears in the print. This is caused by the fact that when damping water is given to the printing plate by means of damping rollers 9 and 10, there is a strong tendency that an exces of damping water adheres to the leading edge portion A of the plate. On account of this, when the plate starts to rotate and comes into contact with the inking roller, an excess of water adheres to the inking roller in a stripe-like manner. When the roller makes further rotation and said portion comes into contact with the metal roller to obtain a supply of ink, sulficient diffusion of the excess water being difiicult to be accomplished by one single metal roller, an inadequate supply of ink on that portion results as compared with other portions, causing the appearance of stripe-like unevenness in the print just at the place corresponding to one revolution of the inking roller.

When such a defect is very conspicuous, a boundary line of dark and light inking appears distinctly in the print and often results in the production of unsatisfactory prints. As a means of solving such a defect, use of inking rollers differing from each other in diameter has been tried. However, by such means it was impossible to obtain a complete solution of the problem to the annoyance of the printers, and is the problem that applicants invention has overcome.

in view of the forgoing, in the present invention all conventional ideas have been discarded and under an entirely new conception an improved ink distributing means has been completed. The present invention is characterized in that at least one of the inking rollers is made of a rubber roller which is large enough in diameter to be able to supply ink to the entire surface of the printing plate dur- 3,100,441 Patented Aug. 13, 1963 ing one revolution of said inking roller, and at the same time these inking rollers are arranged to come into contact with two or more metal rollers which have a reciprocating movement as they rotate in order to get a supply of ink.

The invention will now be described in connection with the accompanying drawing which shows a preferred embodiment.

In accordance with usual practice a plate 12 is secured on a cylinder .13 by means of adjustable clamp 11, (11', numerals 1 and 2 represent inking rollers of large diameter. The roller 1 is so constructed as to have a periphery long enough to cover substantially the distance between A and B of the printing plate .12 during its one revolution. Rollers 3, 4 and 5 are arranged to contact with the inking rollers. The rollers 5 and 6 are metal rollers which have a reciprocating movement while rotatmg.

The ink which comes out from a roll 7 and through an ink transferring roller 8 is well kneaded while it passes between a plurality of rollers and supplied to the inking rollers 1 and 2 uniformly by means of the metal rollers 3, 4, '5 and 6. The metal rollers which come into contact withthe inking rollers 1 and 2 are composed of a plurality of metal rollers as shown in the drawing, so that even if the pattern of the print may be a partial one and the ink may be taken away to the printing plate partially, the ink being well distributed while passing through these metal rollers, and the supply of the ink being accomplished from more than two places, and in connection with these, at least one of the inking rollers, roller [1, being made large enough in its diameter to be able to supply ink uniformly on-to the entire surface of the printing plate, there is no fear of producing of defective prints havink dark and like unevenness. By the use of the invented device it is possible to produce brilliant and elegant prints.

Moreover, due to the reciprocating movement of a plunal-i-ty of metal rollers, the excess of damping Water adhering to the inking rollers -1 and 2 in a stripe-like manner being well dilfused when ink is supplied, there is no fear of the appearance of defective stripes due to the excess of damping water. Thus it will be seen that the annoying defects of prior constructions have been overcome by the present invention.

1 claim:

1. In a printing press having a plate cylinder for mounting a printing plate thereon, the improvement which compn'ses, means for inking said printing plate comprising two inking rolls for inking said plate and disposed radially of said plate cylinder in contact therewith and extending parallel thereto, one of said inking rolls being larger in diameter than the other of said inking rolls and having a circumference of sufficient length to completely ink said plate during one revolution of said one inking roll, said inking roll having a larger diameter comprising a resilient inking roll and being disposed to ink said plate after the other inking roll has made contact therewith, two longitudinally reciprocably driven metal rolls for transferring ink to said inking rolls while rotating and reciprocably driven, one of said reciprocably driven metal rolls being disposed in contact with and parallel to said inking rolls, the other of said reciprocably driven metal rolls being disposed parallel to the inking roller having a lesser diame- 3 ter and in contact therewith two other metal rolls disposed parallel to said inking roller halving the larger diameter and in contact therewith, and other rolls disposed for s-upplying and transferring ink to said reciprocably driven metal rolls, and to said other two metal rolls.

2. In a printing press according to claim 1, in which said press comprises a plurality of dampening rolls coactive with said plate cylinder disposed to dampen said plate before inking by said two inking cylinders.

References Cited in the file of this patent UNITED STATES PATENTS Millison July 24, 1900 Walser et a1. May 3, 1921 Goedike June 16, 1936 Harrold Mar. 23, 1943 Harrold et al. Sept. 7, 1948 

1. IN A PRINTING PRESS HAVING A PLATE CYLINDER FOR MOUNTING A PRINTING PLATE THEREON, THE IMPROVEMENT WHICH COMPRISES, MEANS FOR INKING SAID PRINTING PLATE COMPRISING TWO INKING ROLLS FOR INKING SAID PLATE AND DISPOSED RADIALLY OF SAID PLATE CYLINDER IN CONTACT THEREWITH AND EXTENDING PARALLEL THERETO, ONE OF SAID INKING ROLLS BEING LARGER IN DIAMETER THAN THE OTHER OF SAID INKING ROLLS AND HAVING A CIRCUMFERENCE OF SUFFICIENT LENGTH TO COMPLETELY INK SAID PLATE DURING ONE REVOLUTION OF SAID ONE INKING ROLL, SAID INKING ROLL HAVING A LARGER DIAMETER COMPRISING A RESILIENT INKING ROLL AND BEING DISPOSED TO INK SAID PLATE AFTER THE OTHER INKING ROLL HAS MADE CONTACT THEREWITH, TWO LONGITUDINALLY RECIPROCABLY DRIVEN METAL ROLLS FOR TRANSFERRING INK TO SAID INKING ROLLS WHILE ROTATING AND RECIPROCABLY DRIVEN, ONE OF SAID RECIPROCABLY DRIVEN METAL ROLLS BEING DISPOSED IN CONTACT WITH AND PARALLEL TO SAID INKING ROLLS, THE OTHER OF SAID RECIPROCABLY DRIVEN METAL ROLLS BEING DISPOSED PARALLEL TO THE INKING ROLLER HAVING A LESSER DIAMETER AND IN CONTACT THEREWITH TWO OTHER METAL ROLLS DISPOSED PARALLEL TO SAID INKING ROLLER HAVING THE LARGER DIAMETER AND IN CONTACT THEREWITH, AND OTHER ROLLS DISPOSED FOR SUPPLYING AND TRANSFERRING INK TO SAID RECIPROCABLY DRIVEN METAL ROLLS, AND TO SAID OTHER TWO METAL ROLLS. 